Fuel filter elements supported within a housing, where the housing includes a head and a removable collection bowl, are known, for example, from U.S. Pat. No. 4,626,348. The head includes inlet and outlet ports, and the element is located such that fuel entering the assembly flows between the housing and the element, and then passes inwardly through the filter media for removal of contaminants such as particulate and water. The collection bowl, which is typically transparent, is supported below the head, and is threadably attached to the housing. The bowl includes a drain in its lower end that enables a user to remove water periodically from the collection bowl, as the water is separated from the fuel flowing through the media. A heater element can also be included in the collection bowl, which is used during cold-weather operation, and heats the fuel to facilitate the fuel flowing through the media and then on through the fuel system.
In certain of these assemblies, for example as shown in U.S. Pat. No. 4,626,348, the element is screwed onto a threaded spud depending downwardly from the filter head. A space or gap is provided between the lower end cap of the element and the inside walls of the housing to allow fluid flow into the lower portion of the bowl, where the water collects and can be removed. The lower end cap includes radial ridges which support the element on a shoulder or other support surface in the housing. The element in the '348 patent is retained within a “spin-on” cartridge, and replaced as a unit with other components of the housing. That is, the element cannot be separately removed from the housing and replaced. The lower end cap and walls of the housing include cooperating structure which prevent the element from rotating within the housing, as the collection bowl is directly screwed onto the lower end cap of the element. The collection bowl is attached to the assembly by threads on an internal cylindrical wall of the bowl being received on cooperating threads on a central spud depending downwardly from the lower end cap of the element.
Other assemblies are known, for example as shown in U.S. Pat. No. 4,668,393, where the collection bowl is attached directly to the walls of the housing, rather than to the element. In these case, the housing includes threads provided, e.g., in an attachment ring supported at the distal end of the housing. The collection bowl attaches to these threads, and also forms a seal with the element such that the fluid can pass properly from the periphery of the element into the collection bowl. Radial ridges on the lower surface of the lower end cap support the element on a shoulder formed by the attachment ring, and provide radial channels for flow. The ridges also project radially outward from the periphery of the lower end cap to properly space and align the element within the housing.
U.S. Pat. No. 4,740,299 shows a similar structure incorporating a threaded connecting ring; while U.S. Pat. No. 5,643,466 shows the filter element having radial projections on its lower end cap which support the filter within a shoulder of the can. In the '446 patent the opposite end cap includes an axial projection which engages a valve element to open a flow path through the assembly when a proper element is attached to the filter head.
U.S. Pat. No. 6,171,491 shows still further embodiments where a filter element is supported within the housing, where the housing is a “spin-on” type of cartridge (that is, the element and components of the housing remain together as a unit); and also shows embodiments where the element is removed from the housing when the element is spent, such as being temporarily connected to a threaded cover for the housing, and removed from the upper end of the housing.